Population Bottleneck


Does anyone have information about human population bottlenecks? Something that’s been bothering me is that scientists say there was never a bottleneck that went below maybe 10,000 people and that seems to contradict Scripture and Church teaching that we could’ve come from Adam and Eve. Or that population went down after the Flood.
Thoughts? Links?



It’s not the Catholic position that this actually happened, just a parable to teach us about God. There are so many practical and physical issues with the flood. How could a small number of people feed and clean up after all those animals. How about the ones the writers and Noah would not have know about? Where did all that water come from? If you mix salt water and fresh water it is bound to kill many fish and so on.



You’re Catholic, right?



Exactly which part of scripture? The genealogy, for example, it is my understanding that the Church doesn’t take them literally.

Humani Generis (Pius Xll, 1950) is referenced a lot in these types of discussions because it mentions polygenesis, but I’m not sure the reference is apt. One of the things that are unclear to me is what is meant in the encyclical by the word “polygenesis”. Apparently the word doesn’t mean exactly the same thing today as it did in the 1950’s. Another thing about HG, is that the reference to polygenesis is not necessarily referring to a ban on the theory, but a warning that the theory isn’t yet developed enough to believe in, and cannot be accepted at that time.

Either way, the Church’s interest is in the soul. The existence of an immortal soul in a homo sapien is what makes a human, according to the Church. So the Church, and the story of A&Eve is concerned with the human, not necessarily the homo sapien. Population bottlenecks and genetics should be able to shed some light on humans and their souls, but they would tell us much more about Homo sapiens in general.



What is the flood narrative’s genre?

The Catholic Church does not prohibit interpretations of Genesis 6-8 that include a worldwide flood, but neither does the Church require there to be a worldwide flood in all interpretations of these passages. Instead, Catholic theologians understand the first eleven chapters of Genesis contain, in the words of Pope Pius XII, “simple and metaphorical language adapted to the mentality of a people but little cultured, both state the principal truths which are fundamental for our salvation, and also give a popular description of the origin of the human race and the chosen people” ( Humani Generis , 38).




Given that science also says that all men and women are descended from the same man and woman. My mother’s background is in biology, but she doesn’t doubt Adam and Eve existed. Be careful though, the Bible is not a science textbook. There’s a lot of pseudo science out there (seriously, read Dawkins if you don’t believe me).

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You’re Catholic, right?



The opinion from certain scientists that there was never a human bottleneck that went below 10,000 people is old news and old science. More recent studies suggest otherwise. See the links below:


The findings from the above study concerning the latest on population genetic models is that a bottleneck of two humans cannot be ruled out from 500,000 years or older.

The findings of the Stoeckle and Thaler study apparently reveal that all human beings alive today can be traced to a first couple much less than the 500,000 year mark of the above study, namely, to 100,000 - 200,000 years ago.


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You cannot define a bottleneck since the process of evolution is almost continuous.



I think that you are confusing the bible, which does say that, with science, which emphatically doesn’t.



VERY interesting. Thanks for posting this.



But isn’t that inconsistent with evolution?
My understanding is that mutations happen to one organism that transmits it to their offspring.
So by definition, wouldn’t the earliest populations of humans have to be <10,000?



For one thing, going back to prehistory, there are no records to even estimate population size. So these assertions concerning bottlenecks are pure speculation.



I don’t think I understand your question.



Population bottleneck numbers are assumed.

The study’s most startling result, perhaps, is that nine out of 10 species on Earth today, including humans, came into being 100,000 to 200,000 years ago.

“This conclusion is very surprising, and I fought against it as hard as I could,” Thaler told AFP.

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Don’t let the issue of “population bottleneck” bother you. Just believe what the Bible said, that man – the whole man, not just his soul, – was especially created by God, and that all of humankind descended from the first man and woman, Adam and Eve. There is NO scientific proof that man evolved from a lower form of animals.

I think that the evolution of species is possible, but even that is still an unproved hypothesis. And, even if the evolution of species did happen, it is my faith that man was an exception.

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I think that since the vast majority of scientists believe there IS proof for evolution, there is.

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We do not do science by consensus. The modern synthesis is just about gone. They will hold onto to it as long as they can, but even the top evo’s know it is not the best explanation.



Truth is established by evidence , not by headcount. During the time of Galileo, almost everybody was against him when he said that the earth moves around the sun, not the other way around. We know today that he was right, and the others were wrong, because the evidence was in his favor.

Very good point!



That piece says, “The work of Schaffner and Swamidass has opened up the possibility of a first pair. It cannot be ruled out between about 500,000 years ago and 7 million years ago, when we supposedly split from chimps.” So, if the population did drop as low as two, then it was a long time ago, probably more than 500,000 years. That “supposedly” is a warning flag that the opinions on that site might not be reliable.

Not necessarily a couple. The study looked at mitochondrial DNA, which traces back in the female line to a single women. She may have had two or more male partners, the study could not tell. She was also not alone, there were other females alive at the time, but either their line died out or at some point they only had male children who did not carry their mitochondrial DNA forward.



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